Transmission Problem

[usaf]

I installed a Transmission in my 95 SL320..the problem is I can take it out of park and put it into reverse neutral drive or whatever..BUT when I try to put it BACK in PARK it will NOT go in until I switch off the engine..? Could this be the Neutral Safety Switch..Overload Protection Switch, Throttle Pos. Sensor or the Shift Solenoid..? Any help would be greatly appreciated..can be reached at...or could it be just a reset by disconnecting the battery a certain length of time

david_reeder@sbcglobal.net